Originally Posted By: aualtima3.5
I have some Hankook Optimo 727s that are cracking near the bead/seating part of the tire on the rim. I keep them properly inflated (typically a little over at 32 psi).
Tires have about 40k on them. Car is kept outside. Miles are about 70% highway.
The previous set of tires (Goodyear LS) did the same thing... I am looking for input to understand this. Maybe this is just normal after a few years?
2 thoughts:
1) It is possible what you are seeing is the wax cracking and not the rubber itself. The wax is put in the rubber matrix to form a barrier to outside elements to slow down the degrading of the rubber. The wax flakes off and is replaced by additional wax in the matrix itself which migrates to the surface, forming a new barrier.
To determine if that is the case, look carefully at the cracks. Are they strictly surface crazing and do not penetrate into the rubber to any extent? Likely the wax cracking. Take a photo and post it. I'm sure everyone will have an opinion.
2) Rubber cracks. How long it takes depends on a lot of things. You should expect cracking in a tire, and the question should be how bad is it. Superficial cracking is OK. When it gets some depth, then that is a problem. Posting a picture will help here.
(OK, 3 thoughts!)
Since this is the second set that cracked, is there an ozone problem where you are? Do you change the tires over in winter and store them near a furnace or some electrical device?
